Mallory Prather by Mallory Prather

Yersinia pestis

maprather01 — 2025-04-21 16:44:02 UTC

A Gram-negative, rod-shaped bacterium responsible for one of the most infamous killers in history—the plague. This little demon spreads fast and kills faster if untreated.

Disease It Causes

maprather01 — 2025-04-21 16:46:57 UTC

Plague has three main forms: bubonic, septicemic, and pneumonic. Bubonic is most common and causes swollen lymph nodes called buboes. Pneumonic can spread person to person through droplets—aka airborne doom.

Transmission

maprather01 — 2025-04-21 16:53:37 UTC

Mainly spread through the bite of infected fleas carried by rats, but pneumonic plague spreads through respiratory droplets. Nature said “let’s make this contagious AND deadly.

maprather01 — 2025-04-21 16:54:51 UTC

People in areas with poor sanitation, rodent infestations, or close contact with infected animals. Hunters, campers, and travelers in certain rural areas (like the American Southwest) can be at risk too.

Buboes

maprather01 — 2025-04-21 16:56:40 UTC

Fever, chills, weakness, and buboes (swollen lymph nodes). If it turns pneumonic? Coughing, chest pain, bloody sputum, and rapid respiratory failure. Septicemic form? Skin blackens and dies—hence “Black Death.

Prevention

maprather01 — 2025-04-21 16:58:06 UTC

Avoid contact with wild rodents, control flea infestations, and report dead animals. In some areas, people get preventative antibiotics after exposure—aka plague pre-game.

Treatmeant

maprather01 — 2025-04-21 16:58:58 UTC

Treatment must begin quickly with antibiotics like streptomycin or doxycycline to prevent death.

History and impact

maprather01 — 2025-04-21 17:01:12 UTC

The Black Death in the 14th century wiped out about 1/3 of Europe’s population. That’s how much havoc Yersinia pestis caused. History’s OG mass murderer

Microbial Structure

maprather01 — 2025-04-21 17:02:12 UTC

Gram-negative coccobacillus with bipolar staining (looks like a safety pin under the microscope). Facultative anaerobe that’s sneaky af in the bloodstream.

Facts

maprather01 — 2025-04-21 17:03:14 UTC

Y. pestis is considered a potential bioterrorism agent. Yeah, she’s still a threat in the 21st century. The CDC classifies her as a Category A pathogen.

Summary

maprather01 — 2025-04-21 17:07:20 UTC

Yersinia pestis is a highly virulent, Gram-negative bacterium responsible for causing the plague. It is transmitted primarily through the bites of infected fleas that live on rodents, but pneumonic plague can also be spread through respiratory droplets from person to person. The three main types of plague are bubonic, septicemic, and pneumonic, each with terrifying symptoms ranging from swollen lymph nodes and high fever to internal bleeding and respiratory failure. Those at risk include people in rural areas with rodent exposure, hunters, and individuals in areas with poor sanitation. Prevention includes rodent and flea control, and prompt treatment with antibiotics is essential for survival. Historically, this pathogen wiped out millions and still causes sporadic outbreaks today.